1. Field of the Invention
The present invention relates to a metal hydrides discharge lamp. More specifically, the present invention is directed towards a discharge lamp having a chamber filled with metal, hydrogen or deuterium, and a buffer gas.
2. Description of the Prior Art
High intensity discharge lamps, such as high pressure sodium lamps and metal halide lamps, are well known. These lamps have a light transmissive, hermetically sealed, discharge chamber or tube; the chamber generally has the shape of a pillbox or slightly flatted sphere. The material inside the chamber (the "fill") includes a suitable inert buffer gas and one or more ionizable metals or metal halides.
In a typical lamp, an electric potential is developed between two electrodes in the lamp chamber, which provides energy to the fill in the chamber. In more recent years, a new type of "electrodeless" lamp has been developed, in which an external capacitive or inductive element, such as a coil, is placed in proximity to the chamber. An electromagnetic field generated by passing electricity through the external element provides energy to the fill in the chamber to promote light emission from the fill.
Various standard performance indicators are used to rate different lamps. These factors include luminous efficacy of the lamps, its rated life, lumen maintenance, chromaticity, and color rendering index (CRI). These factors are dependent upon the fill for a particular lamp, which are generally designed to optimize the efficacy and CRI. However, it is believed that these factors can be improved upon, both individually and collectively.